1 files changed, 44 insertions, 4 deletions

diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h
index e4aa9996a550..496e6a8ee0dc 100644
--- a/tools/lib/bpf/bpf_core_read.h
+++ b/tools/lib/bpf/bpf_core_read.h
@@ -29,6 +29,7 @@ enum bpf_type_id_kind {
 enum bpf_type_info_kind {
 	BPF_TYPE_EXISTS = 0,		/* type existence in target kernel */
 	BPF_TYPE_SIZE = 1,		/* type size in target kernel */
+	BPF_TYPE_MATCHES = 2,		/* type match in target kernel */
 };
 
 /* second argument to __builtin_preserve_enum_value() built-in */
@@ -110,21 +111,50 @@ enum bpf_enum_value_kind {
 	val;								      \
 })
 
+#define ___bpf_field_ref1(field)	(field)
+#define ___bpf_field_ref2(type, field)	(((typeof(type) *)0)->field)
+#define ___bpf_field_ref(args...)					    \
+	___bpf_apply(___bpf_field_ref, ___bpf_narg(args))(args)
+
 /*
  * Convenience macro to check that field actually exists in target kernel's.
  * Returns:
  *    1, if matching field is present in target kernel;
  *    0, if no matching field found.
+ *
+ * Supports two forms:
+ *   - field reference through variable access:
+ *     bpf_core_field_exists(p->my_field);
+ *   - field reference through type and field names:
+ *     bpf_core_field_exists(struct my_type, my_field).
  */
-#define bpf_core_field_exists(field)					    \
-	__builtin_preserve_field_info(field, BPF_FIELD_EXISTS)
+#define bpf_core_field_exists(field...)					    \
+	__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_EXISTS)
 
 /*
  * Convenience macro to get the byte size of a field. Works for integers,
  * struct/unions, pointers, arrays, and enums.
+ *
+ * Supports two forms:
+ *   - field reference through variable access:
+ *     bpf_core_field_size(p->my_field);
+ *   - field reference through type and field names:
+ *     bpf_core_field_size(struct my_type, my_field).
+ */
+#define bpf_core_field_size(field...)					    \
+	__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_BYTE_SIZE)
+
+/*
+ * Convenience macro to get field's byte offset.
+ *
+ * Supports two forms:
+ *   - field reference through variable access:
+ *     bpf_core_field_offset(p->my_field);
+ *   - field reference through type and field names:
+ *     bpf_core_field_offset(struct my_type, my_field).
  */
-#define bpf_core_field_size(field)					    \
-	__builtin_preserve_field_info(field, BPF_FIELD_BYTE_SIZE)
+#define bpf_core_field_offset(field...)					    \
+	__builtin_preserve_field_info(___bpf_field_ref(field), BPF_FIELD_BYTE_OFFSET)
 
 /*
  * Convenience macro to get BTF type ID of a specified type, using a local BTF
@@ -155,6 +185,16 @@ enum bpf_enum_value_kind {
 	__builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_EXISTS)
 
 /*
+ * Convenience macro to check that provided named type
+ * (struct/union/enum/typedef) "matches" that in a target kernel.
+ * Returns:
+ *    1, if the type matches in the target kernel's BTF;
+ *    0, if the type does not match any in the target kernel
+ */
+#define bpf_core_type_matches(type)					    \
+	__builtin_preserve_type_info(*(typeof(type) *)0, BPF_TYPE_MATCHES)
+
+/*
  * Convenience macro to get the byte size of a provided named type
  * (struct/union/enum/typedef) in a target kernel.
  * Returns: